Switch frequency
The switch frequency defines when ciphers and or secret keys are renegotiated.
The default time that this renegotiation occurs is once an hour. By using switch options, you can set the time in minutes when the renegotiation occurs.
The longer that the secret key and encryption cipher remain in use, the more likely that the encryption rules might be broken by an attacker. To avoid this, cryptologists recommend periodically changing the secret key and cipher on long-term connections.